Question Regarding Order Tracking Numbers

When a customer orders something from your store, how are they expected to recieve the tracking number for their product? I believe it's not immediately on the receipt since you have to fulfil the order via. aliexpress yourself.

But after you fulfill it and recieve a tracking number, how do you give this to them? via. email, or something else? Because many people don't check their mail. If so, will I need to purchase a custom email address? For example, Support@Name.com? What is the recommended platform to host a shopify store mail address from? Outlook, gmail, or is it a major turn off if there is for example 'gmail.com' in my emails to customers and therefore I will have to resort to custom emails, or is this not the case?

Another question. I understand that the ePacket shipping method grants customers a tracking number, but what about the other aliexpress shipping methods? Some countries don't have epacket, so if I fulfil the product in a certain country with aliexpress shipping, will they give me a tracking number too? How does this work.